The now-overgrown beach resort was once frequented by Yugoslav military elite.

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

Yugoslavia's biggest underground airport lies in ruins.

Outstanding, eerie frescoes and decorations fill this 19th-century monastery.

This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

An abandoned saucer-shaped monument in the Bulgarian mountains.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

Thousands of rusting train cars have been slowly falling apart on the edge of Greece's second largest city.

Monasteries on rock pillars, once accessible only by frayed ropes.

The hallucinogenic center of the ancient world.

This was the second largest mercury mine in the world and one of the oldest preserved mine complexes in Europe.

This former railway facility is the oldest in Slovenia, and now houses a museum showcasing the history of steam locomotives.

Slovenia's first mosque is a striking mix of Islamic and modernist architecture.

A miniature train-ride through Slovenia's largest cave system.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

A cableway for car transport.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

This spaceship sculpture in the middle of the Slovakian capital looks like it just crash-landed.

A unique hotel for the artistic soul.

This abstract sculpture once had a twin in Prague.

Crammed inside this grounded passenger plane is a bar that was once a Communist hang out and is now a ratty relic.